1. Field of the Invention
The present invention relates to fuse holders and, more particularly to such a fuse holder, which is inexpensive to manufacture and, produces low impedance during transmission of electricity.
2. Description of the Related Art
FIGS. 6 and 7 show a fuse holder constructed according to the prior art. According to this design, the fuse holder comprises a base 4, a plurality of metal conducting blocks 5 arranged at the top side of the base 4, a plurality of metal conductive clamps 51 respectively fastened to the metal conducting blocks 5 for securing fuses, and a cover (not shown) covered on the base 4 over the metal conducting blocks 5. Each metal conductive clamp 51 comprises a mounting portion 512 fastened to the bottom side of one metal conducting block 5 and one metal conducting spring plate 7 by screws 52, and a clamping portion 511 bilaterally upwardly extended from one end of the mounting portion 512 and adapted to hold one conducting blade of a fuse. This design of fuse holder has drawbacks as follows:
1. Because each metal conductive clamp 51 is fastened to the mounting portion 512 of the corresponding metal conductive clamp 51 with a respective screw 52, the connection between the metal conductive clamp 51 and the corresponding metal conducting block 5 is not tight, resulting in high impedance and low conducting efficiency between the metal conducting block 5 and the corresponding metal conductive clamp 51.
2. The use of a secondary screw 52 to fasten the mounting portion 512 of each metal conductive clamp 51 to the corresponding metal conductive clamp 51 complicates the installation procedure, increasing the installation cost.
FIGS. 8–10 show another design of fuse holder according to the prior art. According to this design, each metal conducting block 6 has at least one insertion slot 61 adapted to receive one metal conducting spring plate 7, and a bottom notch 62 at the bottom side of each insertion slot 61. After installation of one metal conducting spring plate 7 in one insertion slot 61 of one metal conducting block 6, the bottom bent 71 of the metal conducting spring plate 7 extends to the bottom notch 62. After the cover 8 covered on the base 81 of the fuse holder, the bottom bent 71 is maintained in between the corresponding metal conducting block 6 and the base 81. When in use, the conducting blades 31 of fuses 3 are respectively inserted into the insertion slots 61 of the metal conducting blocks 6 and maintained in close contact with the metal conducting spring plates 7 in the insertion slots 61 of the metal conducting blocks 6. This design of fuse holder is still not satisfactory in function due to the following drawbacks:
1. Due to dimension tolerance, the bottom bent 71 may not fit the bottom notch 62 of the corresponding metal conducting block 6 perfectly, and the metal conducting spring plate 7 may not be positively secured to the inside of the corresponding insertion slot 61, thereby producing a barrier to the insertion of the conducting blade 31 of the fuse 3.
2. Because each metal conducting spring plate 7 has one end fixed and the other end movable for holding down the conducting blade 31 of one fuse, it may be deformed easily or may start to wear quickly with use.